1. Field of the Invention
The present invention relates to seatbelt retractors in which a seatbelt for protecting an occupant is wound up by a biasing force and stored, and more particularly to a seatbelt retractor in which it is contemplated that an oppressive feeling applied to the occupant while the seatbelt is worn by the occupant is reduced.
2. Description of the Prior Art
The seatbelt retractor is adapted to wind up the seatbelt by its biasing force, whereby said biasing force gives an oppressive feeling to the occupant even while he wears the seatbelt around his body, so that the occupant is fatigued with the oppressive feeling, thus resulting in decreased seatbelt wearing rate by the occupants.
Accordingly, a proposal for such a seatbelt retractor has been made that the biasing force for winding up the seatbelt is decreased while the occupant wears the seatbelt to thereby decrease the oppressive feeling to the occupant. In this seatbelt retractor, two springs for winding up the seatbelt are serially connected to each other, while the occupant wears the seatbelt, a pawl is engaged with a ratchet wheel provided at the joint between the two springs, whereby the biasing force of only one spring for winding up the seatbelt is applied to the seatbelt, thereby reducing the oppressive feeling to the occupant.
However, with this seatbelt retractor, in the case the take-up shaft is turned one turn in the wind-up direction, the pawl is disengaged from the ratchet wheel. In this case if the occupant winds out the seatbelt more than a length corresponding to one turn of the take-up shaft and winds up the seatbelt by the same length as above, a large biasing force for winding up the seatbelt is applied to the occupant, and consequently, the zone within which the wind-out and wind-up operations for the seatbelt can be performed, i.e. a comfort zone is significantly small.